Electric vehicle charger capable of stably charging electric vehicles having mutual potential difference

Abstract

An electric vehicle charger of the present invention may comprise: multiple power modules which convert AC supplied from a power system into DC for charging an electric vehicle, and have a mutual potential difference; a distribution blocking unit which blocks or conducts current flowing through a power line between power modules whose outputs are to be interconnected; a circuit breaker which blocks current flowing from a power module to an electric vehicle connected to a power line for charging; and a control unit which controls operations of the power modules, the distribution blocking unit, and the circuit breaker, and obtains information on whether a power module is in a high-voltage or low-voltage state, or whether an electric vehicle is being charged by the power module, before current of another power module is conducted or blocked by the distribution blocking unit.

Description

An electric vehicle charger that can reliably charge electric vehicles with different potentials.

[0001] The present invention relates to an electric vehicle charger capable of simultaneously charging multiple electric vehicles having different potentials and stably charging them while preventing fire or malfunction.

[0002] As the electric vehicle market becomes more active and electric vehicles with various power capacities and voltages appear, safety is required when charging electric vehicles using electric vehicle chargers.

[0003] When charging an electric vehicle, basic safety measures are guaranteed by the electric vehicle itself, but fundamental safety measures may also be needed at the charger to ensure safe charging.

[0004] Most of the conventional charging stations are about how to charge multiple electric vehicles simultaneously, such as a distribution panel that receives electricity and distributes it to each load, a server that stores information on the amount of charging power and the charging time, and a control device for multiple chargers consisting of a main charger and a sub-charger for charging electric vehicles. However, there are few methods for charging electric vehicles that have different types of charging voltages and different potential differences.

[0005] The present invention can safely perform charging even when there is a mutual potential difference between the plurality of electric vehicles while charging the plurality of electric vehicles.

[0006] The electric vehicle charger of the present invention converts AC supplied from a power system into DC for charging an electric vehicle, and may include a plurality of power modules having a mutual potential difference, a distribution blocking unit for blocking or conducting a current flowing in a power line between power modules to be output-connected, a circuit breaker for blocking a current flowing from the power module to an electric vehicle connected to the power line for charging; and a control unit for controlling the operations of the power modules, the distribution blocking unit, and the circuit breaker, and obtaining information on whether the voltage of the power module is high or low, or whether an electric vehicle is being charged in the power module, before conducting or blocking the current of another power module by the distribution blocking unit.

[0007] As electric vehicles diversify, not all electric vehicles are charged at the same voltage. Therefore, when simultaneously charging high-voltage and low-voltage electric vehicles, if a high voltage of approximately 800 V flows to the low-voltage electric vehicle, problems such as fire or malfunction may occur. As part of fundamental safety measures for such electric vehicle chargers, the present invention provides an electric vehicle charger capable of simultaneously charging both low-voltage and high-voltage electric vehicles, and a control method thereof.

[0008] Figure 1 is a configuration description diagram of a power module, a distribution blocking unit, a circuit breaker, and a measuring device of the present invention.

[0009] Figure 2 shows examples of charging situations between a high / low voltage power module of the present invention and a high / low voltage electric vehicle.

[0010] Figure 3 is an explanatory diagram of a high-power charging method that links multiple power modules of the present invention.

[0011] Figure 4 shows a charger structure and control method of the present invention that prevents high-voltage electricity from flowing to a low-voltage electric vehicle.

[0012] Figure 5 is an explanatory diagram of a control step of an electric vehicle charger of the present invention.

[0013] Fig. 6 is another embodiment of Fig. 5.

[0014] Figure 7 is an explanatory diagram of a method for turning off the distribution blocking unit to solve a problem that occurs when electric vehicles with different mutual potentials are simultaneously charged.

[0015] FIG. 8 is another embodiment of FIG. 7, and is an explanatory diagram of a method for keeping the power module off to solve a problem that occurs when electric vehicles with different mutual potentials are simultaneously charged.

[0016] Figure 9 is an explanatory diagram of the output reduction step and charging termination step of the electric vehicle charger of the present invention.

[0017] Referring to FIGS. 1 to 9, the electric vehicle charger of the present invention will be described.

[0018] In FIG. 1, the electric vehicle charger of the present invention may include at least one of a power module (110), a distribution blocking unit (130), a circuit breaker (150), a measuring device (170), a connection unit (190), and a control unit (200). These components may be included in one electric vehicle charger or may be separately included in multiple electric vehicle chargers.

[0019] The power module (110) may be a power conversion unit that converts AC supplied from the power system to DC for charging an electric vehicle for an electric vehicle charger. The power or voltage of each power module (110) may be set differently depending on the location where the electric vehicle charger is installed. A charger installed for personal use may be configured with only a plurality of low-voltage power modules having a predetermined identical power, and a charger installed in an electric bus parking lot may be configured with only a plurality of high-voltage power modules having a predetermined identical power. The present invention relates to an electric vehicle charger that can charge both low-voltage electric vehicles, such as electric passenger cars, and high-voltage electric vehicles, such as electric buses and electric trailers, and may be mainly intended for safe charging so that even when charging simultaneously, electricity from the high-voltage power module does not flow into the low-voltage electric vehicles, resulting in problems such as fire or malfunction.

[0020] A distribution blocking unit (130) is provided on a parallel power line (52) connecting power modules (110) and can block or conduct current between multiple power modules (110).

[0021] A circuit breaker (150) is provided in a series power line (51) connecting a power module (110) and an electric vehicle (EV), and can block not only the current of an additionally connected power module (110B), but also the current of a power module (110A) connected in series with a connection part (190) to which the electric vehicle is connected.

[0022] The measuring device (170) can be installed adjacent to the connection part (190) and can measure or collect power data such as current, voltage, and power of electricity flowing to an electric vehicle (EV) being charged at the connection part (190).

[0023] The connecting part (190) is a coupler that is inserted into an electric vehicle (EV) when charging, or a plurality of them can be connected to the charger cable and coupler according to the power conversion capacity of the power module (110) or the charging request specifications of the electric vehicle (EV).

[0024] The control unit (200) can control a series of operations of an electric vehicle charger, including charging. The control unit (200) can determine whether the power module (110), distribution blocking unit (130), or circuit breaker (150) is turned on or off, and can command the control sequence of the components of the charger of FIGS. 5 and 6.

[0025] One of the main purposes of the present invention is to safely prevent problems that occur when electric vehicles (EVs) requiring multiple different voltages are simultaneously charged by a single charger. Therefore, although a single charger is described as including multiple power modules (110), it is not limited thereto, and may include a case where a power line (50) grid is formed between multiple chargers and power modules (110) by dispensing.

[0026] Figure 2 illustrates the relationship between a power module (110) or power conversion unit that outputs low voltage (Low V) or high voltage (High V) and an electric vehicle (EV) that is charged with low voltage (Low V) or high voltage (High V) or requests an electric vehicle charger to charge. Hereinafter, these may be simply referred to as low voltage power module, high voltage power module, low voltage electric vehicle, and high voltage electric vehicle.

[0027] As such, the electric vehicle charger of the present invention can charge all electric vehicles requiring a wide range of charging voltages, and can safely charge electric vehicles with different voltages simultaneously without risk of fire or other hazards. For example, low-voltage electric vehicles may be general electric passenger cars, and high-voltage electric vehicles may be electric buses or electric cargo vehicles. High-voltage electric vehicles may require several times more voltage and power than low-voltage electric vehicles during charging. For example, the electric vehicle charger can charge all electric vehicles with voltages ranging from 350V to 850V.

[0028] Figure 2 may represent the simplest charging state without a power line (50) that is connected in parallel between power modules (110) or a distribution blocking unit (130) that is installed in the parallel-connected power line (50) to determine whether to block the flow of electricity / power.

[0029] Even if a high-voltage electric vehicle (High V EV) is not charged at the optimal charging speed regardless of whether it is connected to a low-voltage power module (c) or a high-voltage power module (d), there may not be a problem with the charging itself.

[0030] On the other hand, a low-voltage electric vehicle (Low V EV) is normally charged when connected to a low-voltage power module (a), but when connected to a high-voltage power module (b), not only is the charging efficiency reduced, but high-voltage current flows into the EV, which may pose a risk of fire and may cause a malfunction of the EV or charger.

[0031] Consequently, from a charging safety perspective, it may be necessary to prevent current from flowing into the high-voltage power module (110) when charging a low-voltage electric vehicle. In cases where there are no parallel power lines connecting the power modules (110) through a simple series connection, simply marking the couplers connected to the high-voltage and low-voltage electric vehicles may be sufficient.

[0032] However, as the voltage and power required by electric vehicles, such as electric passenger cars and electric buses, are diversified, a charger also needs an electric circuit that interconnects power modules (110), and in order to provide various charging methods, such as rapid charging / slow charging / smart charging, it is necessary to connect power modules (110) in parallel for charging safety.

[0033] In order to ensure safety during charging, the present invention can provide a circuit breaker (150) on a power line (51) connecting a power module (110) and an electric vehicle (EV) in series, and a distribution blocking unit (130) on a power line (52) connecting the power modules (110) in parallel. In other words, the distribution blocking unit (130) and the circuit breaker (150) can function as safety sensors / safety devices to prevent double fire or other problems.

[0034] According to FIG. 3, a first electric vehicle (EV1) with low voltage or high voltage requests charging from a first power module (110A) with low voltage (Low V), and current from a second power module (110B) with low voltage (Low V) can be supplied to the first electric vehicle (EV1).

[0035] According to FIGS. 5 and 6, the control step (S100) of the charger of FIG. 3 will be examined in more detail. FIG. 5 describes the control step (S100) or control method of a charger using a power module (110) capable of supplying the same voltage without a potential difference. ①, ②, ③, ④, and ⑤ shown in FIG. 5 may correspond to ①, ②, ③, ④, and ⑤ shown in FIGS. 3 and 4.

[0036] Before turning on the output of a power module (110) that is distributed to a connection (190) or connected in series to which an electric vehicle (EV) is connected for charging, the operating status of a distribution blocking unit (130) provided in a power line (50) connecting another power module (110) adjacent to the power module (110), or the operating status of a circuit breaker (150) provided in a series power line (51) can be first checked.

[0037] Confirmation of the operating status of the distribution blocking unit (130) or the operating status of the circuit breaker (170) may be confirmation that the distribution blocking unit (130) or the circuit breaker (170) is off, and when the distribution blocking unit (130) or the circuit breaker (170) is off, it may mean that the power line (50) on which the distribution blocking unit (130) or the circuit breaker (170) is installed is blocked so that no current flows.

[0038] Before checking the operating status of the circuit breaker (170), the operating status of the distribution circuit breaker (130) can be first checked. This may be to first check that no current flows from another power module (110) corresponding to another circuit breaker (170) before checking that no current flows along the power line connected in series with the power module (110) corresponding to each circuit breaker (170).

[0039] From FIG. 5 and FIG. 6, as an example, a situation is described in which a first electric vehicle (EV1) requests charging to a connection portion (190A) corresponding to a first power module (110A), and a plurality of power modules are linked to supply power.

[0040] The control unit (200) can confirm that the operation of the first distribution blocking unit (130A) is off and confirm that no current flows in from the surrounding parallel power line (52) (S111).

[0041] The control unit (200) can issue an on command to the first circuit breaker (150A) and check whether the first circuit breaker (150A) is operating properly (S113).

[0042] When the circuit breaker (150) is turned on, if electricity exceeding a preset threshold value, such as a threshold voltage value, flows through the power line (50) on which the circuit breaker (150) is installed, the circuit breaker (150) automatically operates to block the electricity flow. The control unit (200) checking the distribution circuit breaker (130) or circuit breaker (150) may include checking a sensor that prevents electricity exceeding the allowable current / voltage from flowing. This may be because the distribution circuit breaker (130) and circuit breaker (150) function as two safety devices to prevent high-voltage current from flowing to low-voltage electric vehicles.

[0043] The control unit (200) can turn on the output of the first power module (110A), and power can be supplied from the first power module (110A) to the first electric vehicle (EV1) (S115).

[0044] By confirming that the second distribution blocking unit (130B) or the second circuit breaker (150B) is turned off, it can be confirmed that power is not supplied to the first electric vehicle (EV1) through the first distribution blocking unit (130A) (S121).

[0045] Step S121 can be applied when the number of power modules required for charging the first electric vehicle (EV1) is at least three or more for reasons such as rapid charging or power capacity.

[0046] Step S121 can be performed before the output of the second power module (110B) turns on (S125) or before the output of the third power module (110C) turns on (S135).

[0047] It can be confirmed that electricity does not flow to the first electric vehicle (EV1) through the second distribution blocking unit (130B) or the power line provided with the second distribution blocking unit (130B) by performing the operation before the second power module output is turned on (S125) or before the third power module (110C) output is turned on (S135).

[0048] The control unit (200) can issue an on command to the first distribution blocking unit (S123). This step (S123) can be performed before receiving electricity from the second power module (110B) or before the output of the second power module (110B) is turned on (S125).

[0049] The output of the second power module (110B) can be supplied to the first electric vehicle (EV1) together with the output of the first power module (110A).

[0050] The same process as for the second power module (110B) can be performed for the third power module (110C).

[0051] The control unit (200) can confirm that the operating status of the third distribution blocking unit (130C) or the third circuit breaker (150C) is off (S131). This step (S131) ​​can confirm that power is not being supplied to the fourth power module (110D) or the like through the power line on which the third distribution blocking unit (130C) or the third distribution blocking unit (130C) is installed from another power module, such as the fourth power module (110D).

[0052] The control unit (200) can issue an on command to the second distribution blocking unit (110B) and check whether the second distribution blocking unit (110B) is turned on.

[0053] The control unit (200) can issue an output on command to the third power module (110C), and the power of the third power module (110C) can be supplied to the first electric vehicle (EV1).

[0054] The above description may relate to charging a first electric vehicle (EV1) by connecting the power of three power modules (110A, 110B, and 110C). Furthermore, the charging process may involve connecting three power modules that do not have a mutual potential difference, either high or low voltage (Fig. 3).

[0055] If a potential difference occurs between power modules (Fig. 4), rather than immediately issuing an on command to the circuit breaker (150) or the distribution blocking unit (130), before performing an operation to supply or cut off power to another power module, it is necessary to obtain information such as whether the power module (110) has high or low voltage, or whether another power module (110) is charging an electric vehicle. In this case, issuing an on command to the distribution blocking unit (130) (S123) or issuing an on command to the circuit breaker (150) (S113) can have an expanded meaning.

[0056] According to FIG. 6, the circuit breaker command or on command step (S113) may include a step of obtaining information about the power module (110) and the electric vehicle (EV) connected to the circuit breaker (130) (S113a), a step of determining whether the circuit breaker (130) is on or off (S113b), or a step of determining whether the power module (110) is on or off connected to the circuit breaker (130) (S113c).

[0057] At step S113b, electricity is allowed to flow through the power line (50) on which the circuit breaker (130) is installed, and when the set threshold is exceeded, the circuit breaker (130) can perform a blocking operation.

[0058] In step S113a, when an electric vehicle (EV) is connected to the connection unit (190) for charging, information about the EV can be transmitted to the control unit (200) along the power line (50). If the EV is a low-voltage EV and the connected power module (110) is a high-voltage one ((b) of FIG. 2), there is a risk of fire or failure, so the control unit (200) may not turn on the output of the power module (110) (S113c). Accordingly, if there is a different connection relationship ((a), (c), (d) of FIG. 2) between the power module (110) and the electric vehicle (EV) in step S113a, the control unit (200) may make an on decision to the circuit breaker (S113b) and turn on the output of the power module (110) (S113c).

[0059] In addition, the command or command step (S123) for the distribution blocking unit (130) may include information on another power module to be output-linked, information on whether another electric vehicle is being charged to the other power module, or if charging is taking place, information acquisition step (S123a) on the other electric vehicle, an on or off decision step (S123b) for the distribution blocking unit (130), and an on or off decision step (123c) for another power module to be output-linked.

[0060] The on or off decision (S113b) for the circuit breaker (150) may be the same as the on or off decision (S113c) for the power module (110) connected to the circuit breaker (150). For example, if the first circuit breaker (150A) is on, the first power module (110A) may also be on, and if the first circuit breaker (150A) is off, the first power module (110A) may also be off.

[0061] On the other hand, the on or off decision (S123b) for the distribution blocking unit (130) may be the same as the on or off decision (S123c) for another power module (110) to be output-linked, but may also be determined differently. If the on or off decision (S123b) for the distribution blocking unit (130) and the on or off decision (S123c) for another power module (110) to be output-linked are different, the on or off decision may be affected by whether the electric vehicle is being charged in the other power module to be output-linked.

[0062] FIG. 7 and FIG. 8 illustrate a case where a first electric vehicle (EV1) with a low voltage requests charging by connecting to a first power module (110A) with a low voltage, and the second power module (110B) to which an output connection is to be requested is high voltage, thereby preventing the electricity of the second power module (110B) from being supplied to the first electric vehicle (EV1). FIG. 7 and FIG. 8 have in common that the current of the second power module (110B) with a high voltage is not supplied to the first electric vehicle (EV1), but whether the distribution blocking unit (130) is turned off (FIG. 7) or whether the second power module (110B) is turned off (FIG. 8) may differ.

[0063] In Fig. 7, when a second electric vehicle (EV2) is already being charged in the second power module (110B), the first distribution blocking unit (130A) can be turned off so as not to affect the on / off of the second power module (110B) that is supplying power to the second electric vehicle (EV2) during the output connection process of the first electric vehicle (EV1). However, in this case, the output of another power module may not be connected to the first electric vehicle (EV1).

[0064] On the other hand, in FIG. 8, if no other electric vehicle is being charged in the second power module (110B), the control unit (200) can turn off the second power module (110B). In this case, there may be a difference in that the output can be linked to another power module, such as the third power module (110C), compared to turning off the distribution blocking unit (130).

[0065] The control unit (200) can reduce the power output supplied to the electric vehicle (EV) for reasons such as switching from rapid charging to slow charging or approaching the charging completion point (S200).

[0066] The output reduction step (S200) may include an output off step (S210) of another output-linked power module (e.g., a third power module (110C), a step (S230) of checking whether there is an output reduction corresponding to the output off of the third power module (110C) by checking the measurement value of the first measuring device (170A), or a second distribution blocking unit off step (S250).

[0067] This case may be a case where the first power module (110A) to the third power module (110C) are connected to charge the first electric vehicle (EV1) connected to the first circuit breaker (150A).

[0068] To further reduce the output, the output of the second power module (110C) can be turned off in the same way (S230), and the first distribution blocking unit (130A) can be turned off (S250).

[0069] When charging is completed (S300), the output of all remaining power modules can be turned off (S310), the measurement value of the first measuring device (170A) can be checked to confirm that no power is supplied to the first electric vehicle (EV1) (S330), and all remaining distribution cutoffs (130) and the first circuit breaker (170A) can be turned off (S350).

[0070] In this way, by turning off all of the distribution blocking units (130) or circuit breakers (150) that operate for electric vehicle (EV) charging, it is possible to reliably confirm that there is no current leakage through the power line (50) grid. Consequently, since the distribution blocking units (130) and circuit breakers (150) are kept off until they are turned on in the charging control step (S100) according to the charging request, power consumption can be reduced, and electricity from the high-voltage power module can be safely prevented from flowing to the low-voltage electric vehicle.

Claims

1. Multiple power modules that convert AC supplied from the power grid into DC for charging electric vehicles and have a mutual potential difference; A distribution circuit breaker that blocks or energizes the current flowing through the power lines between power modules to be output-linked; A circuit breaker for blocking the current flowing from the power module to the electric vehicle connected to the power line for charging; and An electric vehicle charger comprising: a control unit that controls the operation of the power module, the distribution breaker, and the breaker, and obtains information on whether the power module is at high or low voltage, or whether an electric vehicle is being charged in the power module, before the distribution breaker conducts or blocks current to another power module.

2. In paragraph 1, The above power line includes a first power line that connects the power module and the electric vehicle in series, and a second power line that outputs and connects current between the power modules. When the first electric vehicle is charged through the first power line corresponding to the first power module, An electric vehicle charger, wherein the control unit first checks the operating status of a distribution blocking unit that connects the output of the second power module to the first electric vehicle, or the operating status of the first circuit breaker of the first power line, before turning on the output of the first power module.

3. In paragraph 1, Before checking the operating status of the circuit breaker, the above control unit first checks the operating status of the distribution circuit breaker, An electric vehicle charger wherein the above control unit first confirms that no current flows from another power module before confirming that no current flows along the first power line connected in series with the power module corresponding to each circuit breaker.

4. In paragraph 1, The on or off decision for the above distribution blocking unit can be determined differently from the on or off decision of other power modules to be output-linked. An electric vehicle charger in which the on or off decision for the above distribution blocking unit is different from the on or off decision for another power module to be output-linked, and is determined based on whether an electric vehicle is being charged in the other power module to be output-linked.

5. In paragraph 1, When the first electric vehicle, which is low voltage, requests charging by connecting to the first power module, which is low voltage, and the second power module, which requests output connection, is high voltage, and the second electric vehicle is being charged in the second power module, An electric vehicle charger in which the above control unit turns off the first distribution blocking unit so that power from the second power module is not supplied to the first electric vehicle.

6. In paragraph 1, If the first electric vehicle with low voltage requests charging by connecting to the first power module with low voltage, and the second power module to request output connection is high voltage and no other electric vehicle is being charged in the second power module, An electric vehicle charger wherein the control unit turns off the second power module and attempts to connect output with a third power module that is different from the first or second power module.

7. In paragraph 1, The first electric vehicle is charged through the first power line having the first circuit breaker corresponding to the first power module. The first distribution block or the second distribution block is provided on the second power line that transmits current between the power modules, The above control unit confirms that the operation of the first distribution blocking unit is off and confirms that no current flows in from the second power line. The above control unit, An on command is given to the above first circuit breaker, Turn on the output of the above first power module, The above first distribution blocking unit is given an on command, The output of the second power module is turned on, An electric vehicle charger in which the output of the second power module is supplied to the first electric vehicle together with the output of the first power module.

8. In paragraph 1, The above power line includes a first power line that connects the power module and the electric vehicle in series, and a second power line that outputs and connects current between the power modules. An electric vehicle charger wherein the above distribution blocking unit is provided on the second power line, and the circuit breaker is provided on the first power line.

9. In paragraph 1, Includes a measuring instrument that measures power data supplied to the electric vehicle, The above control unit, If the power output supplied to the above electric vehicle decreases, the output of the output-linked power module is turned off, the measurement value of the measuring instrument is checked to confirm whether the output decreases corresponding to the output off of the output-linked power module, and the distribution blocking unit is turned off. An electric vehicle charger that turns off the output of the remaining power modules when charging of the electric vehicle is finished, checks the measurement value of the above measuring device to confirm that there is no power being supplied to the electric vehicle, and turns off the remaining distribution blocking section and circuit breaker.

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